In a lengthy interview published on Saturday, Republican presidential frontrunner Donald Trump said he has avoided being too specific about his foreign policy views because he “wouldn’t want [adversaries] to know what my real thinking is.”

In the 100-minute interview about foreign policy, conducted by the New York Times on Friday, Trump answered questions about using nuclear weapons, defeating ISIS and the problems with NATO.

Asked how he would handle tensions in the South China Sea, Trump said he would use better trade deals to negotiate with China—something he has routinely promised to do during his campaign—but he declined to be more specific about his strategy.

“Would I go to war? Look, let me just tell you. There’s a question I wouldn’t want to answer,” Trump said. “I don’t want to say what I’d do because, again, we need unpredictability. You know, if I win, I don’t want to be in a position where I’ve said I would or I wouldn’t. I don’t want them to know what I’m thinking.”

“The problem we have is that, maybe because it’s a democracy and maybe because we have to be so open – maybe because you have to say what you have to say in order to get elected – who knows?” he continued. “But I wouldn’t want to say. I wouldn’t want them to know what my real thinking is. But I will tell you this. This is the one aspect I can tell you. I would use trade, absolutely, as a bargaining chip.”